<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			.box1{
				width: 200px;
			}
			.box2{
				width: 300px;
			}
			.box3{
				width: 400px;
			}
			.box1,.box2,.box3{
				height: 100px;
				background-color: red;
				margin-bottom: 10px;
			}
		</style>
	</head>
	<body>
		<div class="box1">box1</div>
		<div class="box2">box2</div>
		<div class="box3">box3</div>
	</body>
</html>
